Geology is the science that studies the planet Earth, particularly its solid part, especially the earth’s crust, the matter that makes it up, its formation processes and its evolution from its origin to the present day. Through Geology, society has access to a variety of energy and natural resources, such as oil, metals, lime, quartz, phosphorus, nitrogen, sulfur, chlorine and others. Also of economic interest is the study of groundwater systems (hydrogeology) and soil (pedology), mainly for agriculture. In addition, Geology helps in safe construction of houses and cities (geotechnics), in prevention of damage due to natural disasters and in conservation of natural environments. To do this, it is necessary to understand the structure of the planet Earth, its age and its history through the lens of the theory of plate tectonics. According to this theory, the rigid lithosphere, formed by the crust and the upper mantle, is fragmented into several tectonic plates that move over the plastic asthenosphere. This phenomenon is called tectonism and in a sense it is responsible for the entire geological situation of the earth’s crust, made up of three main types of rocks (igneous, sedimentary and metamorphic). Various are the disciplines that make up the geological science, such as crystallography, mineralogy, sedimentology, igneous and metamorphic petrology, paleontology, structural geology, tectonics, geochemistry, astrogeology and others. The publication history of geological literature in Esperanto is quite interesting. Pioneering works are La bela subtera mondo: libro pri grotoj (“The Beautiful Underworld: A Book of Grottoes”, Leander Tell, 1959) and El la polvo de la tero: enkonduko en la grundosciencon (“From the Dust of the Earth: An Introduction to Soil Science”, William F. Rolt, 1967); the journal Geologio Internacia (“International Geology”, ISAE, first volume published in 1968); and the reference works Ĉu vi konas la Teron? (“Do You Know the Earth?”, Endre Dudich, 1983, published by UEA) and Geologia Vortaro (“Geological Dictionary”, edited by Tom Arbo Høeg, 1989, published by the University of Oslo). It is important to get acquainted with this science, which gives interesting job opportunities and is applied in a wide variety of fields.